Vimentin is is highly expressed in cells of mesenchymal origin, as well as in most transformed cell lines and tumors. Like other intermediate filament (IF) proteins, intracellular vimentin is important for stabilizing the architecture of the cytoplasm, and contributes to specific dynamic cellular process such as mechanical stability, migration and wound healing.5,6,7 
Vimentin is abundant in human monocytes, activated macrophages and in multinucleated giant cells.8 Increased vimentin expression is a late event in the differentiation of human monocytic cells.9,10 Human monocytes cultured in 40% human serum differentiate into monocyte-derived macrophages (MDM). These cells take on the characteristics of in vivo activated tissue macrophages, becoming multi-nucleated, and secreting proteases that destroy connective tissue elements.11,12 Prior to the present disclosure, extracellular secretion of vimentin and its role in inflammation and anti-pathogen activity was unrecognized. Thus, effective methods of screening for the contribution of secreted vimentin to physiologic or pathologic pathways are clearly needed, as are modulators of vimentin bioavailability for use in the treatment of secretory vimentin-mediated pathologies.